Actually, you don't have to start fresh. I assume you are using grub as you bootloader. Do the following:
When at the kernel selection, go into edit mode and append
to the line that starts with linux
Continue booting and you will eventually be dropped to a shell. Type
mount -o remount,rw /
to allow write access to your root filesystem. Then, a simple
will let you change your login password for the user <username>, without knowledge of the old pw. Also worsk for root, of course.
Reboot and you will be able to login again.
I don't see any violation of the forum guidelines here. The information I posted is available throughout the internet in numerous places. Neither do I encourge or empower anyone to do anything illegal. Since smturner1 obviously has physical access to the machine in question, I assume he gained it in a legitimate way. So holding back this information, just because there is the remote chance that he uses it to cause mieschief doesn't seem acceptably to me.